(a) Field of the Invention
This invention relates to certain 11(eq)-(CH.sub.2 CH.sub.2 CH.sub.2 -R.sub.5)-hexahydro-2,6-methano-3-benzazocines, generally useful as morphine-like analgesics and as narcotic antagonists.
(b) Description of the Prior Art
There are several references in the literature, especially the patent literature, to 1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocines having lower-alkyl substituents containing up to six carbon atoms in a side chain attached to the 11-position of the hexahydro-2,6-methano-3-benzazocine nucleus. However, these references specifically disclose only 11-methyl-substituted benzazocines (Akkerman et al. U.S. Pat. No. 3,764,606 and Schubert et al. U.S. Pat. No. 3,733,330); or 11-methyl and 11-ethyl-substituted compounds (Merz et al. U.S. Pat. No. 3,981,874). There are no known references, either in the scientific or the patent literature, which disclose such hexahydro-2,6-methano-3-benzazocines having 11-alkyl chains containing four or more carbon atoms, and there are only occasional species of 1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocines specifically disclosed in the patent literature where the 11-alkyl side chain contains a three carbon group, i.e. propyl (for example Rahtz et al. U.S. Pat. No. 4,020,164, column 7, lines 26-27). Ager et al., J. Med. Chem., 6 (3), 322-325 (1963) and Rice et al., J. Med. Chem., 18 (8), 854-857 (1975), disclose that, by increasing the bulk (i.e. the chain length) of 9-lower-alkyl-6,7-benzomorphans (or named as 11-lower-alkyl-1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocines using alternative nomenclature), the potency is diminished as the lower-alkyl group is lengthened from methyl to ethyl to propyl.